1. Field of the Invention
This invention relates to the field of computer device systems, and more particularly this invention pertains to a digitizer input system having local storage and an adaptive data transfer policy for extending the battery of an interfaced computing device, such as a PC.
2. Description of the Prior Art
Personal computing devices, including PC's, are generally comprised of a number of systems. For instance, a PC may be comprised of a user interface, including at least one user input system; a graphics display system; a memory storage system; a power system; etc. PC systems add functionality to the PC. While adding desired functionality, PC systems also typically require the use of PC resources in order to operate and provide their desired functionality. For example, PC systems may rely on the CPU and memory device(s) of the PC for processing and storage of data, respectively. PC systems may also rely on the PC's power source for electrical power.
A digitizer input system is an example of a user input system. A digitizer input system typically has a pen input device (i.e., stylus) and a digitizer grid. The digitizer input system tracks the relative position of the input pen as the input pen is pressed on or near the digitizer grid as is known to those skilled in the art. The digitizer input system provides an apparatus and method for a user to input commands and other information, such as handwritten text, into the interfaced PC for use, processing, storage, and display. Prior art digitizer input systems rely on the CPU and storage devices of the interfaced PC for providing the necessary processing and storage means for tracking, processing, and storing the positional data generated by the digitizer input system. The additional use of the PC's resources, such as, but not limited to, the CPU and memory requires the PC to use additional electrical power.
Portable companion computing devices, including PCs and other devices having input device systems, are becoming increasingly popular. Portable computing devices typically use a battery as a source of electrical power. Due to a companion computing system's reliance on the resources (e.g, the CPU and/or memory) of the PC interfaced with the companion computing system, companion computing systems tend to decrease the useful battery life of the computing device (e.g., PC) interfaced thereto.